<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="shortcut icon" href="./favicon.ico"/>
    <title>首页</title>
</head>
<body>
    <h2>空空雨夜</h2>
    <button>点击获取用户数据</button>
    <script>
       const  btn = document.querySelector('button');
       btn.onclick = function(){
           const xhr = new XMLHttpRequest();
           xhr.open('GET', 'http://localhost:9000/data');
           xhr.send();
           xhr.onreadystatechange = function(){
               if(xhr.readyState === 4){
                   if(xhr.status >= 200 && xhr.status < 300){
                       console.log(xhr.response);
                   }
               }
           }
       }
    </script>
</body>
</html>